We read with interest the article by Esteve-Taboada et al.1 The authors measured the modulation transfer function (MTF) of three intraocular lenses (IOLs) using a corneal eye model with zero spherical aberration using monochromatic light. This means that corneal higher order aberrations and chromatic aberration were not taken into account for the evaluation, even though it has been shown that s...

If we talk about Stellar Aberration, then think of the form Aberration that was first discovered and explained by Bradley. In addition to Bradley's which can also be defined as Relative will define Absolute based on just one measurement. Here after refer $ASA$. We try explain in a few words why it is necessary measure interpret this way. Suppose performed two measurements Doppler Effect within ...

Advancements in cataract surgery and intraocular lens (IOL) design have optimized the postoperative optical performance of the pseudophakic eye. One of the recent spotlights of IOL design has been formulating optical properties similar to a clear, young lens and addressing spherical aberration. Spherical aberration in the human eye is a combination of the positive spherical aberration of the co...

PURPOSE To develop a prototype instrument that uses adaptive optics to introduce virtually any desired aberration profile in a subject's eye. At the same time, the instrument could be used to evaluate the subject's spatial vision for each controlled aberration profile. This "aberration testing station" or "visual simulator" allows us to study the relationship between specific aberrations and vi...

purpose: to determine the outcomes of visual correction with femto-lasik following pk. methods: in this prospective study, 34 eyes of 31 patient who had undergone thin – flap lasik due to high refractive error after corneal grafting were evaluated .after complete ocular examination and assessment of uncorrected and corrected distant visual acuity (ucva and bcva) , the patients underwent femto-l...

The expansion of wavefront-sensing techniques redefined the meaning of refractive error in clinical ophthalmology. Clinical aberrometers provide detailed measurements of the eye's wavefront aberration. The distribution and contribution of each higher-order aberration to the overall wavefront aberration in the individual eye can now be accurately determined and predicted. Using corneal or ocular...

PURPOSE To assess the compensation of total ocular and corneal wavefront aberrations after conventional myopic LASIK. METHODS This study comprised 57 eyes of 57 patients. Total and corneal aberrations were measured preoperatively and 3 months postoperatively using the OPD-Scan (NIDEK Co Ltd) aberrometer. Total and corneal aberrations root-mean-square (RMS) was calculated out to the 6th Zernik...

During the last decade aberration correction became possible for several types of electron optical instruments. Correctors for the spherical aberration of TEM / STEM objective lenses are now commercially available [1,2]. In case of the SEM [3] and the LEEM / PEEM [4] the correction of both the spherical and the chromatic aberration has been demonstrated in experiments. In spite of these great a...

PURPOSE The aim of this study was to design and evaluate in the laboratory a new intraocular lens (IOL) intended to provide superior ocular optical quality by reducing spherical aberration. METHODS Corneal topography measurements were performed on 71 cataract patients using an Orbscan I. The measured corneal surface shapes were used to determine the wavefront aberration of each cornea. A mode...

PURPOSE To compare the effect of spherical aberration on optical quality in eyes with two different aspherical intraocular lenses. METHODS 120 eyes of 60 patients underwent phacoemulsification. In patients' eyes, an aberration-free IOL (Aspira-aA; Human Optics) or an aberration-correcting aspherical IOL (Tecnis ZCB00; Abott Medical Optics) was randomly implanted. After surgery, contrast sensi...